How to measure air quality in your home

How to measure air quality in your home

Do you suspect that the air inside your house may be contaminated? Here are some signs of contamination and how to go about identifying them.


Mould is a type of tiny fungi that develop on damp or decomposing organic materials.

Health impacts:

While non-toxic, mould can trigger typical allergic reactions such as red and watery eyes, rashes, sore throat, headache and memory loss.


  • Look for it in areas where mould is most likely to appear, like the bathroom, laundry room, shower, as well as the basement and confined spaces where there is little or no air circulation, around windows and crawlspaces.
  • Watch out for:
    • Leaks and water stains
    • Odours: certain types of mould give off a distinctive musty, mouldy or stale smell
    • Excessive condensation

Carbon monoxide

Carbon monoxide, or CO, is a gas that can have nasty effects on your health and may even cause death. It is odourless, colourless and tasteless.

Carbon monoxide is produced by burning fuel – wood, oil, gas, coal, natural gas and propane. It is also found in second-hand smoke.

Wood stoves and combustion appliances can release carbon monoxide into the air if they aren’t properly installed or maintained.

Generators, cooking appliances and BBQs can also give off carbon monoxide as can car exhausts and blocked chimneys.

Health effects:

  • When CO is inhaled, it reduces your body’s ability to carry oxygen in the blood. The symptoms resemble the flu: fatigue, shortness of breath, headache, muscular weakness.
  • Prolonged exposure to low concentrations or exposure to high concentrations can cause chest pain, blurred vision and confusion.
  • Exposure to very high concentrations can lead to convulsions, coma and death.


  • Install a certified carbon monoxide detector.


Like carbon monoxide, radon is an invisible, odourless, and tasteless gas. It is radioactive and is produced by the natural decay of uranium in the soil and bedrock.

It is harmless if released into the air but may pose a health risk in high concentrations in closed spaces.

Health effects:

  • It damages lung cells and can cause lung cancer.


  • Install a radon detector.
  • Get a certified radon specialist to conduct a long-term test (at least three months).

If radon concentrations exceed 200 Bq/m3, the Canadian guideline, get a certified radon professional to determine the most cost-effective way for you to reduce levels.

Installing a radon mitigation system may be recommended. These systems can be installed in a day and lower radon concentrations by more than 80%.

It’s important to know that a number of household products including glue, paint, varnishes and plastic/wood composites release chemical pollutants into the air. Discard any of these you no longer use and get into the habit of airing out your home with each change of season.

If you have any misgivings about the air quality in your home, see a professional.